We are studying experimentally the intracellular mechanism "lipid droplet formation" as a part of the overall process of the transport and secretion of long chain triglycerides through the intestinal absorptive cell. One important aspect is the production and/or release of chylomicrons, the end producer of the lipid secretory process. The experiments have been principally concerned with the stimulation of lipid secretion by the calcium ion. The experiments employ sacs of the everted intestine of hamster and other species. During the experiments, the sac takes up oleic acid and monoolein from a bile salt solution in the mucosal fluid. The secretory stage of intracellular fat absorption is then observed. We observed that addition of calcium ion to the mucosal fluid promotes the secretion of chylomicron-like particles into the serosal fluid. We are performing experimental variations of that secretory process using quantitative and morphological observational methods.